It's pretty much a Bittorrent/Edonkey world these days. Even the private nets are now mostly torrents. I don't think there is a L7 filter for it, it's so slow it wouldn't make sense to block it, and not useful enough like bittorrent for legit uses. Just throttle the user instead if they are abusing it.

Its for a network at WORK... my employees are downloading Limewire to get Mp3's and I need to block access at the router level, that way I won't have to keep uninstalling, only to have them re-install it.

The computers that are used are community computers, so throttling a particular computer hurts everyone not just the idiots downloading limewire.

Don't forget you can also encourage them to use 'internet streaming radio' instead which will still give them something to listen to in the cubicle farm but is low bandwidth as it's one way, and low bitrate (128 kbit usually).

But yeah, QOS is the best solution because at the end of the day, if they have 'install' abilities on the PCs, and there is at least ONE port open, they can always set up something remotely to act as a tunnel and will continue to merrily download away. Threats aren't good for morale either.

BassKozz, were you successful in blocking Limewire? I also tried the suggested blocking via IPP2P and L7...both were unsuccessful. I know the MAC addresses of the PC's, so I ended up blocking all ports except 53, 80, and 443 until I figure out how to successfully block Limewire.